<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title></title>
    <script>
      //es6继承-先声明父类，在声明子类，通过extends继承方法,通过super()继承属性
      class User {
        constructor(name, pass) {
          this.name = name;
          this.pass = pass;
        }

        showName() {
          console.log(this.name);
        }
        showPass() {
          console.log(this.pass);
        }
      }

      class VipUser extends User {
        constructor(name, pass, level) {
          super(name, pass); //继承父类上的属性  super指代了整个prototype或者__proto__指向的对象
          this.level = level;
        }
        showLevel() {
          console.log(this.level);
        }
      }
      var v1 = new VipUser("blue", "123456", 3);
      v1.showName();
      v1.showPass();
      v1.showLevel();
    </script>
  </head>
  <body></body>
</html>
